Container valve with tripping device for fire extinguishing plants

ABSTRACT

A container valve for fixed fire extinguishing systems comprises a valve body ( 12 ), a closure piston ( 26 ), one sealed end of which is introduced into the release chamber ( 24 ) and the opposite end of which has a sealing surface which can be pressed against a valve seat ( 22 ). Said closure piston ( 26 ) has a pressure compensation channel ( 36 ). A closing spring ( 32 ) exerts a spring force on the closure piston ( 26 ) in the direction of the valve seat ( 22 ). A trigger device ( 46 ) enables a drop in pressure to be created in the release chamber ( 24 ), in such a way that the closure piston ( 26 ) is displaced away from its valve seat ( 22 ), coming to rest against an end stop. A sealing element ( 38 ) seals the pressure compensation channel when the closure piston ( 26 ) rests against the end stop. Said sealing element ( 38 ) can be displaced from the exterior between a sealing position and a filling position, whereby in the sealing position, it seals the pressure compensation channel ( 36 ) of the closure piston ( 26 ) when the latter is in its end position, and in the filling position, it exposes the pressure compensation channel ( 36 ) of the closure piston ( 26 ) when the latter is in its end position.

[0001] The present invention relates to a container valve with atripping device for stationary fire extinguishing plants.

PRIOR ART

[0002] Great demands are made on a container valve with a trippingdevice for stationary fire extinguishing plants. It has to: (1) securelyblock the gas pressure in the extinguishing substance container untilthe plant is released (in high-pressure plants, the gas pressure in thecontainer can be more than 300 bar); (2) be reliably releasable by atripping mechanism as simple as possible; (3) offer the emanatingextinguishing substance only a low resistance to flow (i.e. comprise avalve seat with a large cross-section); and (4) remain securely openedafter the release.

[0003] Most of the container valves with a tripping device forstationary fire extinguishing plants are today embodied as so-calledarticulated-lever valves. However, these valves have the disadvantagethat they require a relatively high tripping force for actuating thearticulated lever. It has therefore been already proposed to constructcontainer valves with a tripping device for stationary fireextinguishing plants as differential pressure valves. Such adifferential pressure valve comprises a closing piston which is mountedin a valve body to be slidably movable in the axial direction andcomprises a sealing face at a first end with which it can be pressedagainst a valve seat. The opposite end of the closing piston isintroduced in a tripping chamber to seal it and here embodies a pressureface which is larger than the free cross-section of the valve seat. Apressure compensation channel transverses the closing piston andconnects the tripping chamber with an inlet channel. When the valve isclosed, in the tripping chamber thus the same pressure resides as in theinlet port. This means that a force of pressure is exerted on theclosing piston in the direction of the valve seat keeping the valvesecurely closed. The valve further comprises a tripping device whichgenerates a pressure drop in the tripping chamber when a release iseffected. After the reduction of the counter-pressure in the trippingchamber, a force of pressure acts on the closing piston which presses itaway from its valve seat against a limit stop. By this action, the valveopens, so that the pressure medium can flow through the valve seat intothe outlet port. The limit stop for the closing piston is formed by asealing plate against which the mouth of the pressure compensationchannel is pressed. That means that in this position the pressurecompensation channel is sealed against the tripping chamber, so that nomore counter-pressure can form in the tripping chamber, not even if thepressure is no longer reduced via the tripping device. In other words,the valve remains securely opened after the release. In order to closethe valve of the emptied container, the tripping chamber is vented viathe tripping device, so that a closing spring can press the closingpiston onto the valve seat.

[0004] In stationary fire extinguishing plants, however, suchdifferential pressure valves could not yet succeed as an alternative toarticulated-lever valves. This is among others due to the fact that thefilling of the pressure container with such differential pressure valvesis relatively difficult. Indeed, the filling cannot be effected via theconnecting piece of the valve, as in the process the closing pistonwould be pressed into its sealed end position and one would have no morepossibility of closing the valve. It has therefore been proposed toarrange a separate filler port below the valve seat. However, even withthis separate filler port, the filling must be effected extremelycarefully, as in case of a fast increase of pressure in the filler port,the closing piston can be lifted from its valve seat.

OBJECT OF THE INVENTION

[0005] Therefore, the object, among others, underlying the presentinvention is to propose a container valve with a tripping device forstationary fire extinguishing plants in a differential pressureconstruction which enables an easy filling of the container.

GENERAL DESCRIPTION OF THE INVENTION

[0006] According to the invention, this object is achieved by a valveaccording to claim 1. The valve according to the invention alsocomprises, as do the differential pressure valves described in thebeginning, a sealing element which seals the pressure compensationchannel in the closing piston, when the latter is in its end position.In contrast to the known valves, however, this sealing element is notfixed in the valve body but can be actuated from the outside between asealing position and a filling position, wherein in the sealing positionit seals the pressure compensation channel of the closing piston in theend position and in the filling position it trips the pressurecompensation channel of the closing piston in the end position. Now, thevalve can be directly filled via the outlet port. In correspondence to apreferred procedure, the sealing element is brought into its fillingposition before the filling operation. The dynamic forces exerted on theclosing piston by the incoming filling flow are in fact in most casessufficient for holding the closing piston in an open position againstthe action of the closing spring. If, however, the filling flow isinterrupted, the dynamic forces of pressure acting on the closing pistondisappear. The resultant of the static forces of pressure acting on theclosing piston also equals zero as the sealing element is in the fillingposition and the container pressure can consequently constitute via theopen pressure compensation channel in the tripping chamber. The closingpiston is thus in pressure equilibrium and is now pressed onto the valveseat by the spring force of the closing spring. To summarize, one cansay that the valve closes immediately after the interruption of thefilling flow if the sealing element has been brought into its fillingposition before the filling operation. Instead of bringing the sealingelement into its filling position before the filling, it is alsopossible to effect the filling with the sealing element being in thesealing position. For the valve to close, the sealing element then hasto be brought into the filling position after the interruption of thefilling flow. This procedure is to be employed if the forces of flowduring the filling are not sufficient for retaining the closing pistonin an open position. With both procedures, the sealing element isreturned to its sealing position after the filling in order to preparethe valve for the next release.

[0007] The sealing element can still be a sealing plate against whichthe mouth of the pressure compensation channel is pressed. In thisembodiment, however, there is the problem that this sealing plate alsohas to fulfill the function of a buffer for the accelerated closingpiston. In the process, the sealing plate is in most cases deformed bythe relatively small sealing face surrounding the mouth of the pressurecompensation channel such that it has to be exchanged already after thefirst release of the valve. The present invention has also solved thisproblem. That is, it is proposed to form the sealing element by a pin inthe tripping chamber which can be introduced into the pressurecompensation channel, the sealing being effected radially via an O-ring.In this embodiment with a radial sealing, the sealing element no longerhas to fulfill a buffer function so that it does not have to beexchanged after every release. A separate annular buffer element whichhas essentially the same external diameter as the tripping chamber andthus a relatively large buffer face can then far more effectivelycushion the impact of the closing piston on the limit stop.

[0008] The tripping device advantageously comprises a control valveintegrated in the container valve and advantageously having thefollowing design. A vent channel ends in the tripping chamber, a controlvalve seat facing the tripping chamber. A closing body is assigned tothe control valve seat such that the pressure in the tripping chamberpresses the closing body axially against the control valve seat of thevent channel, wherein the closing body seals the vent channel. Anoperating tappet to be accessed from the outside makes it possible topress the closing body away from its control valve seat in order to ventthe tripping chamber.

[0009] A particular compact and simple valve design is achieved byarranging the control valve in the axial extension of the pressurecompensation channel and forming the sealing element by a pin at theclosing body of the control valve. As already described above, this pincan be axially introduced into the pressure compensation channel of theclosing piston, the sealing between the pin and the pressurecompensation channel being effected radially via an O-ring.

[0010] In an advantageous, particularly simple embodiment, this controlvalve then furthermore comprises a control valve body in which the ventchannel and the control valve seat are arranged, with this control valvebody being screwed from the outside between a first and a secondposition. In the first position, the pin seals the pressure compensationchannel via the O-ring if the closing body abuts the control valve seatand the closing piston is in its end position. In the second position,the pin opens the pressure compensation channel to the tripping chamberif the closing body abuts the control valve seat and the closing pistonis in its end position.

[0011] The tripping device further comprises an operating device for thecontrol valve, which can be simply pinned onto the valve body in anadvantageous embodiment. The control valve body is in this caseadvantageously embodied such that in the second position it projectsfurther from the valve body than in the first position. This avoids apinning of the operating device onto the valve body as long as the valvebody is not screwed back into its first position in order to prepare thevalve for the next release.

DESCRIPTION WITH REFERENCE TO THE FIGURES

[0012] In the following, now one aspect of the invention is describedwith reference to the enclosed Figures. In the drawings:

[0013]FIG. 1 shows a longitudinal section through a valve with a controlvalve according to the invention, the valve being closed and the controlvalve not being operated;

[0014]FIG. 2 shows a longitudinal section as in FIG. 1 directly afterthe release, the valve being open and the control valve being operated;

[0015]FIG. 3 shows a longitudinal section as in FIG. 1 during theemptying of the extinguishing substance, the valve being open and thecontrol valve being in the meantime operated again;

[0016]FIG. 4 shows a longitudinal section as in FIG. 1 during thefilling, the valve being open and the control valve being in the fillingposition;

[0017]FIG. 5 shows a longitudinal section as in FIG. 1 after thefilling, the valve being again closed and the control valve still beingin the filling position;

[0018]FIG. 6 shows a longitudinal section through an operating devicefor the control valve.

[0019] The valve 10 shown in FIGS. 1 to 5 is a container valve fortripping stationary fire extinguishing plants. It is particularlysuitable for the high-pressure range (i.e. of about 60 to 300 bar) amongothers with inert gas or carbon dioxide as extinguishing substance.

[0020] The valve 10 has a differential pressure design. It comprises avalve body 12 with an inlet channel 14 and an outlet channel 16. Theinlet channel 14 is embodied in a screwed socket 18 which is screwedinto an extinguishing substance container (not shown). The outletchannel 16 is accommodated in a lateral connecting socket 20 of thevalve body 12. Between the inlet channel 14 and the outlet channel 16, avalve seat 22 is arranged. A tripping chamber 24 is axially opposite thevalve seat 22 in the valve body 12.

[0021] Reference numeral 26 designates a closing piston which isintroduced in the tripping chamber 24 with its rear end so as to sealit. Here, the sealing is effected via an O-ring 28 which is inserted ina surrounding groove of the closing piston 26. At its leading end, theclosing piston 26 comprises a front sealing ring 30 with which it can bepressed to the valve seat 22. In the tripping chamber 24, a closingspring 32 is assigned to the closing piston 26 which exerts a springforce thereon in the direction of the valve seat 22, at the same timebeing supported by a screwed plug 34 which is screwed into the valvebody 12 so as to seal it and axially defines the tripping chamber 24.The closing piston 26 is axially transversed by a pressure compensationchannel 36 via which the tripping chamber 24 is in a pressurecommunication with the inlet channel 14.

[0022] In the axial extension of the pressure compensation channel 36,in the tripping chamber 24 a pin 38 is arranged. The latter can beaxially introduced into the pressure compensation channel 36 (see FIGS.2 and 3), an O-ring 40 ensuring a radial sealing of the pin 38 in thechannel 36. (The pin 38 consequently forms a sealing element of thepressure compensation channel 36 and is hereinafter referred to as“sealing pin 38”.) It should be noted that the O-ring 40 is fixed in theclosing piston 26 by means of an annular piece 42, this annular piece 42forming at its front end a conical cavity 44 for introducing the roundedtip of the sealing pin 38 into the pressure compensation channel 36 in aself-locating manner.

[0023] Reference numeral 46 designates a control valve which is builtinto the screwed plug 34 in the axial extension of the pressurecompensation channel 36. This control valve 46 comprises a control valvesleeve 48 which is screwed into an axial threaded bore 50 of the screwedplug 34 and is radially sealed below this threaded bore 50 by means ofan O-ring 52 in a cylindrical chamber of the screwed plug 34. Thecontrol valve sleeve. 48 is axially transversed by a vent channel 54 andcomprises a control valve seat 56 towards the tripping chamber 24 viawhich the vent channel 54 ends in the tripping chamber 24. In the ventchannel 54, an operating tappet 58 is mounted with a radial clearance.This operating tappet 58 supports a closing body 60 in the trippingchamber 24 which is assigned to the control valve seat 56 such that thepressure in the tripping chamber 24 presses the closing body 60 axiallyagainst the control valve seat 56. In the process, an O-ring 62 at theclosing body 60 seals the vent channel 54 against the tripping chamber24. The operating tappet 58 makes it possible to press the closing body60 from the outside into the tripping chamber 24, i.e. away from thecontrol valve seat 56, resulting in the venting of the tripping chamber24 via the vent channel 54. It should be noted that the sealing pin 38is a projection of the closing body 60. As the operating tappet 58 ismounted in the vent channel 54 with a radial clearance, the sealing pin38 has sufficient free motion for centering itself easily in thepressure compensation channel 36.

[0024] By means of the FIGS. 1 to 5, now the functioning of the valve 10is described.

[0025] In FIG. 1, the valve is in the non-released position of rest. Thecontainer pressure prevailing in the inlet channel 14 has alsoconstituted in the tripping chamber 24. As the cross-section sealed inthe tripping chamber 24 by the O-ring 28 is essentially larger than thesealed cross-section at the valve seat 22 and moreover an atmosphericpressure prevails in the outlet port 16, a positive force of pressureacts on the closing piston 26 in the direction of the valve seat 22. Thelarger the container pressure, the larger is this positive force ofpressure, so that it is always ensured that the valve 10 securely blocksa high gas pressure in the container until the plant is released. Itshould be noted that the container pressure also keeps the control valve46 in the closing position.

[0026] If the valve 10 is to be released, the valve tappet 58 has to bepressed inwards, so that it presses the closing body 60 away from thecontrol valve seat 56 resulting in the venting of the tripping chamber24 via the vent channel 54. It should be noted that the force requiredfor the release is relatively small as the cross-section of the controlvalve seat 56 is very small. As soon as the tripping chamber 24 isvented via the control valve 46, the pressure in the tripping chamber 24drops. The positive force of pressure acting on the closing piston 26consequently becomes smaller and finally even becomes negative, i.e. itnow acts in the direction of the screwed plug 34. If this negative forceof pressure becomes larger than the spring force acting in the directionof the valve seat 22, the closing piston 26 is lifted from the valveseat 22 and is accelerated in the direction of the screwed plug 34. Inthe process, the sealing pin 38 penetrates the pressure compensationchannel 36 and seals the latter. Now, no more compressed gas can flowvia the pressure compensation channel 36 into the tripping chamber 24and the closing piston 26 is accelerated in the direction of the screwedplug 34. Reference numeral 61 in FIG. 1 designates an annular bufferelement from an elastic material which is fixed at the front of theclosing piston 26 and essentially comprises the same external diameteras the tripping chamber 24. This relatively large-surface buffer elementeffectively cushions the impact of the accelerated closing piston 26 onthe screwed plug 34 without a sealing face being damaged in the process.

[0027] In FIG. 2, the valve is shown in a position in which the closingpiston 26 in the end position abuts the screwed plug 34, the controlvalve 46 still being operated, i.e. opened. The arrow 62 represents aforce of operation which presses the operating tappet 58 downwards. Thesealing pin 38 should also be noted, which projects into the pressurecompensation channel 36 and seals the latter in the O-ring 40, so thatno more compressed gas can flow into the tripping chamber 24.

[0028] In FIG. 3, the valve is shown in a position in which the closingpiston 26 in the end position abuts the screwed plug 34, the controlvalve 46, however, is now non-operated, i.e. closed. No more force ofoperation now acts on the operating plug 58, so that the pressure in thepressure compensation channel 36 presses the sealing pin 38 upwardsresulting in the closing body 60 being again pressed against the controlvalve seat 56 with its O-ring 62 and closing the control valve 46. Itshould be noted that the valve 10, however, still remains securelyopened as no essential counter-pressure can constitute in the trippingchamber 24 via the pressure compensation channel 36 closed by thesealing pin 38.

[0029] When emptying the container, the force of pressure acting on theclosing piston 26 in the direction of the screwed plug 34 becomesgradually smaller. If this force of pressure finally becomes smallerthan the spring force of the closing spring 32, the closing spring 32moves the closing piston 26 into the direction of the valve seat 22.Thereby, a light negative pressure constitutes in the tripping chamber24 which in turn opens the control valve 46 so that more external aircan flow into the tripping chamber 24 and the closing piston 26 cancontinue its closing movement up to the valve seat 22.

[0030] In FIG. 3, the valve 10 is shown during the filling of thecontainer. It should be noted that the control valve sleeve 48 isscrewed out of the screwed plug 34 by a certain distance X. In thisposition, the sealing pin 38 of the closing body 60 abutting the controlvalve seat 56 is in the filling position, i.e. it can no longer seal thepressure compensation channel 36. The filling of the container is noweffected via the outlet channel 16. At the beginning of the fillingoperation, the filling pressure here acts on the annular face 64 of theclosing piston 26 surrounding the valve seat 22 (see FIG. 1). The forceof pressure resulting therefrom is greater than the spring force actingin the direction of the valve seat 22, so that the closing piston 26 islifted from the valve seat 22 and is accelerated in the direction of thescrewed plug 34. At the same time, the closing body 60 freely hanginginto the tripping chamber 24 is accelerated in the direction of thecontrol valve seat 56 and pressed against the control valve seat 56 bythe pressure which constitutes via the pressure compensation channel 36in the tripping chamber 24, so that the vent channel 54 is sealed. Aslong as the filling flow flows in through the outlet channel 16 at ahigh speed, important forces of flow act on the closing piston 26 andkeep it away from the valve seat 22 against the spring force of theclosing spring 32. If, however, the filling flow is interrupted, thedynamic forces of pressure acting on the closing piston 26 disappear.The resultant of the static forces of pressure acting on the closingpiston 26 also equals zero as the sealing pin 38 is in the fillingposition and the container pressure can consequently constitute via theopen pressure compensation channel 36 in the tripping chamber 24. Theclosing piston 26 is thus in pressure equilibrium and is now pressedonto the valve seat 22 by the spring force of the closing spring 32. Tosummarize, one can say that the valve 10 closes immediately after theinterruption of the filling flow if the sealing pin 38 has been broughtinto its filling position before the filling process by partly screwingout the control valve sleeve 48.

[0031] Instead of bringing the sealing pin 38 into its filling positionbefore the filling operation by partly screwing out the control valvesleeve 48, it is also possible to effect the filling with the sealingpin 38 being in the sealing position. With this procedure, the valve 10is only closed by partly screwing out the control valve sleeve 48 afterthe interruption of the filling flow. This procedure is to be employedin particular if the forces of flow with the sealing pin 38 being in thefilling position are not sufficient during the filling for retaininggthe closing piston 26 in an open position.

[0032] The position of the valve after the interruption of the fillingflow is shown in FIG. 5. In order to achieve the rest position ready tobe released in FIG. 1, the control valve sleeve 48 only has to bescrewed back into its starting position in which the sealing pin 38 isin its so-called sealing position.

[0033] In the shown valve 10, the operation of the sealing pin 38between the sealing position and the filling position is consequentlyeffected by screwing the control valve sleeve 48 between a first and asecond position. The end of the control valve sleeve 48 projecting outof the screwed plug 34 is in this case advantageously designed to placea handwheel thereupon (not shown), so that the operation of the sealingpin 38 between the sealing position and the filling position can beeffected as the opening and closing of a normal valve. As shown in FIGS.4 and 5, the control valve sleeve 48 projects in its second position,i.e. in the filling position of the sealing pin 38, further from thescrewed plug 34 than in its first position, i.e. in the sealing positionof the sealing pin 38 (see FIGS. 1, 2 and 3). This prevents an operatingdevice from being placed upon the valve body if the sealing pin 38 isnot in its sealing position.

[0034] Such an operating device 70 is shown in FIG. 6. It comprises abase 72 which can be axially inserted into a complementarily designedholder 74 at the face of the valve body 12 and is secured therein bymeans of a lock washer 76 which locks into place in an annular groove 78at the base 72. It is obvious that the base 72 cannot be secured in theholder 74 as long as the control valve sleeve 48 is not screwed into thescrewed plug 34 up to its first position.

[0035] Reference numeral 80 in FIG. 6 designates a tappet. If theoperating device 70 is secured with its base 72 in the holder 74 at theface of the valve body 12, the tappet 80 makes it possible to press downthe operating tappet 58 in the control valve sleeve 48 in order to openthe control valve.

[0036] In the operating device 70 of FIG. 6, the tappet 80 is connectedwith a pressure piston 82 which can be supplied with a pressure medium.Here, a readjusting spring 84 fixes a retracted position of rest of thetappet 80.

[0037] It is, however, an advantage of the described valve that it canbe easily equipped with various operating devices which are with theirstandard bases simply inserted into the holder 74 at the front of thevalve body 12. It should be in particular noted that the exchange of theoperating device can be even effected without problems in the valve 10on which a pressure acts. As for the opening of the control valve 46relatively small tripping forces are required, it is easily possible toemploy even relatively weak operating devices, such as electromagneticor thermal operating devices, with the valve 10.

1. Container valve with tripping device for stationary fireextinguishing plants, comprising: a valve body (12) with an inletchannel (14) and an outlet channel (16), a valve seat (22) arrangedbetween the inlet channel (14) and the outlet channel (16) as well as atripping chamber (24) axially opposed to the valve seat (22); a closingpiston (26) which is slidably movable within the valve body (12) axiallyrelative to the valve seat (22), this closing piston (26) being insertedwith one end in the tripping chamber (24) so as to seal the chamberwhere it forms a pressure face, and which comprises a sealing face atthe opposite end with which it can be pressed against the valve seat(22), and wherein the closing piston (26) comprises a pressurecompensation channel (36) via which the tripping chamber (24) is inpressure communication with the inlet channel (14) with the closingpiston (26) lying on the valve seat (22); a closing spring (32) which isassigned to the closing piston (26) such that it exerts a spring forceon the same in the direction of the valve seat (22); a tripping device(46, 70) in communication with the tripping chamber (24); wherein viathe tripping device (46, 70) a pressure drop can be generated in thetripping chamber (24), so that the closing piston (26) is lifted fromits valve seat (22) and by the differential pressure is moved away fromthe valve seat (22) into an end position against a limit stop; a sealingelement (38) for sealing the pressure compensation channel if theclosing piston (26) is in its end position; characterized in that thesealing element (38) can be actuated from the outside between a sealingposition and a filling position, wherein in the sealing position itseals the pressure compensation channel (36) of the closing piston (26)in the end position and in the filling position it opens the pressurecompensation channel (36) of the closing piston (26) in the endposition.
 2. Differential pressure valve according to claim 1,characterized in that the sealing element (38) can be screwed from theoutside between its sealing position and its filling position. 3.Differential pressure valve according to claim 1 or 2, characterized inthat the sealing element (38) is formed by a pin in the tripping chamber(24) which can be inserted into the pressure compensation channel (36),the sealing being effected radially via an O-ring.
 4. Differentialpressure valve according to claim 3, characterized by an annular bufferelement (61) which has essentially the same outer diameter as thetripping chamber (24).
 5. Differential pressure valve according to oneof claims 1 to 4, characterized in that the tripping device (46, 70)comprises a control valve (46).
 6. Differential pressure valve accordingto claim 5, characterized in that the control valve (46) comprises: avent channel (54) ending in the tripping chamber (24); a control valveseat (56) facing the tripping chamber (24); a closing body (60) assignedto the control valve seat (56) such that the pressure in the trippingchamber (24) presses the closing body (60) axially against the controlvalve seat (56) of the vent channel (54), wherein the closing body (60)seals the vent channel (54); and an operating tappet (58) for pressingthe closing body (60) away from its control valve seat (56). 7.Differential pressure valve according to claim 6, characterized in thatthe control valve (46) is arranged in the axial extension of thepressure compensation channel (36) in the closing piston (26), and thesealing element (38) is formed by a pin (38) at the closing body (60) ofthe control valve (46), wherein this pin (38) can be axially introducedinto the pressure compensation channel (36) of the closing piston (26)and the sealing between the pin (38) and the pressure compensationchannel (36) is effected radially via an O-ring (40).
 8. Differentialpressure valve according to claim 7, characterized in that the controlvalve (46) comprises a control valve sleeve (48) in which the ventchannel (54) and the control valve seat (56) are arranged, this controlvalve sleeve (48) being screwable from the outside between a first and asecond position, wherein: in the first position, the pin (38) seals thepressure compensation channel (36) via the O-ring (40) if the closingbody (60) abuts the control valve seat (56) and the closing piston (26)is in its end position; and in the second position, the pin opens thepressure compensation channel (36) to the tripping chamber (24) if theclosing body (60) abuts the control valve seat (56) and the closingpiston (26) is in its end position.
 9. Differential pressure valveaccording to claim 8, characterized in that the tripping device (46, 70)furthermore comprises an operating device (70) for the control valve(46) to be placed upon the valve body (12); and the control valve sleeve(48) in the second position projects further from the valve body (12)than in the first position, thus preventing a placing of the operatingdevice (70) onto the valve body (12).
 10. Differential pressure valveaccording to claim 9, characterized in that the operating device (70)comprises a base (72) which can be axially inserted into acomplementarily designed holder (74) at the face of the valve body (12)and is secured therein by means of a lock washer (76).